Patent GB-190802985-A (GB)
Title: Improvements relating to Electrically Operated Ammunition Hoisting Apparatus.
Inventor: JUSTICE PHILIP MIDDLETON
Filed: 1908-02-10
Granted: 1908-12-03
Abstract: 2985. Justice, P. M., [Otis Elevator Co.]. Feb. 10. Loading-appliances.- Relates to electrically-operated ammunition hoists, and comprises means for stopping the ammunition cage at different positions corresponding to the different elevations of the gun. The hoist comprises a cage C, to which the ammunition may be transferred by a small carriage 8 running on rails 9, suspended by a cable E passing to a drum D driven from the motor M and balanced by a counterweight W connected to it by a cable 4. At the upper end of the run is a stop L comprising a bar 18 suspended by a pin and slot 20 from a member 19 attached to a cable 28 passing to a sheave 30 connected to one of the trunnions of the gun. Pivoted to the member 19 are inclined arms 21 carrying pawls 22 adapted to operate with fixed racks 27 when the ascending cage engages the bar 18. Buffer devices 24, 25 are provided to absorb any shock. A system of levers or other means may be employed for obtaining a movement of the stop L in unison with that of the gun. Fig. 3 shows the arrangement of the controlling-gear in which the motor M is controlled by a hand switch 33 and by a switch 69 regulated by connexions with the drum D and with the trunnions of the gun to slow down or cut out the motor to stop the cage at the limits of its travel. The operation of the hand switch into the first " up " position effects the closing of the power circuit at the switch 40 by the coil 41 and the removal of the brake K. In the second position the starting resistance 42 is cut out by the coil 53, and in the third position the resistances 43, 44, 45, 46, and subsequently 47 are cut out by energizing the coil 48. As the carrier reaches the upper limit of its travel, the switch 69 will have rotated to cause the insulating-section 84 to run under the brush 103, when the circuit of the coil 48 is broken, and the resistances 43 ... 47 are re-inserted. Shortly afterwards the insulating section 83 runs under the brush 102 and the circuit of the coil 53 is broken and the resistance 42 is re-inserted. The motor now runs at a low speed, and the car C abuts against the buffers 24 and causes the pawls 22 to be thrown out. The cage is then held up against the stop L by the torque of the motor. Or the motor may be arranged to be cut out and the brake K applied. As the hand switch 33 moves over its central position to reverse, the switch 40 is broken by the coil 41 and the brake is applied. In the " down " position the motor is connected up as a braking-generator through the contact 66 with the starting-resistances and the additional resistances 62, 63, 64 in circuit, and the brake released. As the cage reaches the lower end of its run, the brushes 154; 127 are electrically connected by the strip 76 to bring the coil 53 into action according to the speed to cut the resistance 42 out of circuit. The brushes 153, 129 are next connected by the strip 78 to bring the magnet 58 into action to short-circuit the resistances 62, 63, 64. As the insulated section 81 runs under the brush 150, the coil 110 is cut out and the brake is applied. Fig. 2 shows a form of automatic stop switch 69 in which the strips 74 ... 78 are spirally mounted on the periphery of a drum'86 mounted on a screw shaft 88. The drum is actuated from the hoisting- drum D through a sprocket-wheel 92 and cross-head 90. The brushes 100 ... 103 which are connected to the contacts on the " up " side of the hand switch 33, are mounted on an arm 99 carried by a disk integral with a sprocket 95 connected by a chain with a sprocket on the trunnions of the gun, so that the position of the arm together with that of the shaft changes as the inclination of the gun alters. The remaining brushes, such as 150, are carried on arms projecting from a fixed disk 105.